Patients with cancer may report neuropsychiatric abnormalities including cognitive impairment, behavioral disturbances, and psychiatric disorders that potentially worsen their quality of life, reduce their treatment response, and aggravate their overall prognosis. Neuropsychiatric disturbances have a different pathophysiology, including immuno-inflammatory and neuroendocrine mechanisms, as a consequence of oncologic treatments (chemo- and radio-therapy). Among clinicians involved in the management of such patients, psychiatrists need to pay particular attention in recognizing behavioral disturbances that arise in oncologic patients, and determining those that may be effectively treated with psychotropic medications, psychotherapeutic interventions, and an integration of them. Through the contribution of different clinicians actively involved in the management of oncological patients, the present review is ultimately aimed at updating psychiatrists in relation to the pathophysiological mechanisms responsible for the onset of cognitive, affective, and behavioral syndromes in these patients, along with epidemiologic and clinical considerations and therapeutic perspectives.